StoGuard Almost Perfect on Joint Base Lewis-McChord Air Barrier Testing

Test results 50% better than allowable maximum air leakage

ATLANTA - (August 19, 2010) Sto Corp., the innovative world leader in cladding, coating, and restoration systems, announces that its StoGuard fluid-applied air and moisture barrier showed significant air tightness during a recent blower door test on a project at Joint Base Lewis-McChord in Washington state.

In October of 2009, the United States Army Corps of Engineers (USACE) created requirements for building air tightness and building air leakage testing for new and renovation Army construction projects in or after Fiscal Year 2010. The testing, in accordance with ASTM E 2178, must demonstrate that the air leakage rate of the building envelope does not exceed 0.25 cfm/sq ft.

The project, which used the StoGuard system, passed with flying colors. Where an acceptable score for the assembly would be 0.25 cfm/sq.ft. the assembly scored 0.18 cfm/sq.ft. in initial testing, and 0.11 in final testing - a difference of 56% less air leakage.

The building tested, the Special Operations Forces (SOF) Aviation Battalion Education Center, is part of the larger Joint Base Lewis-McChord Whole Barracks Renewal project. The barrier system, along with StoGuard Fabric, StoGuard Tape, and StoGuard Primer, was applied to this building and tested in late July.

At Joint Base Lewis-McChord, StoGuard "performed at a level that has not been accomplished since the USACE requirement for such testing began," says Benham Hansen, the ACI-certified-project superintendent. "It is very uncommon after the initial test to accomplish more than a 0.02 or 0.03 difference for the final test. We were able to achieve a 0.07 decrease in cfm."

Neudorfer Engineers, Inc., which conducted the testing at Joint Base Lewis-McChord, expressed similar commendation for the wall assemblies, confirming to Hansen in correspondence that the Education Center is "the highest-performing building they have ever been associated with."

"This was one of the first projects I've seen the StoGuard application go on, and it was one of the better tests I've seen," says Phil Emory, senior project manager at Neudorfer. "0.11 cfm is extremely low and the results were because of the StoGuard product and application. This is a sensational building with an excellent product."

Lisa Petsko, StoGuard Product Manager, said, "We are proud of these results proving the effectiveness of StoGuard. Energy-efficiency of the building will also be positively affected as well. This is key to creating sustainable projects that will continue to perform at a high level for year after year."

A full copy of the test results can be found on the Sto Corp. website HERE.

Details of the actual test

Neudorfer Engineering utilized the two-point method for a negative pressure building per ASTM E-1827-96 (Reapproved 2007). This is the conclusion of the test:

Pref : 0.30 inches H2O

Allowable Leakage per square foot: 0.25 cfm/ft²

Actual Leakage per square foot: 0.11 cfm/ft²

Result: 56% below allowable ratings

Allowable Leakage (building): 2,108 cfm

Actual Leakage (building): 5,151 cfm

Result: 57% below allowable ratings

The test conditions, as stated in the final report, confirmed that the barrier was complete and that all exterior doors (but not all doors) had finishes installed. The doors were taped. All walls were complete. Flooring and baseboard were in progress and wall outlets were not complete. The mechanical system rough-in was complete and all exterior dampers were closed and sealed. The barometric relief damper in the auditorium was also covered with plastic.

Some photography available. Contact Michael Sweeney at or call 678-553-3278.

About StoGuard®

StoGuard® is an efficient assembly of products that combine to create a waterproof air barrier in wall construction. By protecting the backup assembly (sheathing or CMU) first, this seamless spray-on building wrap provides superior protection against moisture intrusion and air leakage.

The StoGuard® assembly consists of the following:
o StoGuard® joint and rough opening treatments - various options available.
o Sto Gold Coat? and Sto EmeraldCoat? are both vapor permeable, waterproof membranes applied by spray or roller to wall sheathing, prepared concrete, or concrete masonry wall construction. Sto Gold Coat® is specially formulated for use under EIFS and other claddings. Sto EmeraldCoat? is a high perm membrane that can be used under various claddings.
o StoGuard® VaporSeal(TM) functions as an air, vapor and moisture barrier. The secondary moisture protection provided by StoGuard® VaporSeal(TM) protects walls against moisture damage from rain during the construction process and in the event of a breach in the wall cladding while in service.

Together these components create a seamless, structural air and waterproof barrier that greatly improves indoor occupant comfort and reduces energy costs. StoGuard can be used underneath brick, metal panels, cement siding, cement stucco and exterior insulation and finish systems. StoGuard is ASTM 2357 compliant and has ICC code recognition.

About Sto Corp.
Sto Corp., based in Atlanta, Georgia, is an innovative world leader and producer of a broad range of versatile cladding and coating systems for building construction, maintenance and restoration. Sto Corp. is ISO 14001:2004 (environmental management) as well as ISO 9001:2008 certified and operates production plants strategically located to serve more than 200 distributor shipping locations across North America. At research and development laboratories in the U.S. and Europe, Sto continues to revolutionize the industry with the highest quality products and application technology.

For more information, visit or call toll free (800) 221-2397 or (404) 346-0755. Follow Sto Corp. on Twitter as well as the Sto blog "Building with conscience" at

For more information contact:
Michael Sweeney, LEED Green Associate
Sto Corp., 678-553-3278

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